I like Jah and I think he can develop substantially from where he is now. His defense was ignored at Duke (since his offense was crucial), and he's missed about a year of pro development time due to injuries.
All that being said, I don't think he's worth a cornerstone player to a young team yet, and the odds are that he never will be. His value, assuming normal to slightly above normal growth (compensating for the injury time and deficient defensive coaching), is "good rotational player," someone who is between the 5th and 10th player on a roster. And the team that acquires him will have to be OK with a more traditional style of post play, or Jah will have to learn to make quicker decisions on the offensive end. Could he be Marc Gasol on the upside? I guess. But he could also be Nik Vukovich.
Oh, and he's cheap because he's on a rookie contract--cheap in dollars, not in assets.
Would Orlando trade Vuk straight up for Jah right now?